[oslc-core] Creating multiple resources in one POST?

[Arthur Ryman]

Andy,

There are also simple command line tools that can easily POST files - curl 
and wget. These can be scripted.

Regards, 
___________________________________________________________________________ 

Arthur Ryman 

DE, PPM & Reporting Chief Architect
IBM Software, Rational 
Toronto Lab | +1-905-413-3077 (office) | +1-416-939-5063 (mobile) 





From:
Andrew J Berner/Dallas/IBM at IBMUS
To:
Arthur Ryman <ryman at ca.ibm.com>
Cc:
John Arwe/Poughkeepsie/IBM at IBMUS, oslc-core at open-services.net
Date:
10/17/2011 01:12 AM
Subject:
Re: [oslc-core] Creating multiple resources in one POST?


Arthur Ryman said:  I am not a fan of multi-create since I don't see 
what's wrong with the 
client just doing multiple POSTs.   (then, and I appreciate this, 
continued to explain how it might be done).

Let me explain why I suggested this, when it's obvious that the "client" 
could just do multiple POSTs.   And while potentially an issue, it's not 
the performance of the network traffic I'm concerned about...

One of the advantages of the use of HTTP based technology for the api is 
that a lot can be done through a browser, especially with plugins that 
allow you to POST with headers etc.  A lot of us (most of us?  all of us?) 
make use of this to test out the api's before we write code---just do the 
GETs, POSTs and PUTs through a browser, copying and pasting the right 
URL's that through code we would get through RDF parsing.

But this actually can be a viable technique for some quick integrations. 
If the end user can get at the needed resources (maybe through GETs from 
another tool or a dedicated export), then the end user can also do the 
POST.  So imagine (and I have in my pocket a good example that's not 
public info yet if anyone wants to communicate privately) a tool that 
could generate a fairly large set of resources that would be good to POST 
to another tool through OSLC.  The first tool could generate a set of 
RDF/XML files in the format the other tool expects.  Maybe the vendor can 
commit the resources to do that, or it could be through a field services 
contract.  Then the end user could use a browser plugin to GET the 
services document from the receiving tool, choose the desired 
creationFactory and POST the resources.  If the POST would support 
multiple resources, this is easy for the customer---have a "canned" POST 
setup in the browser plugin, log into the actual tool (which gives the 
browser plugin authorization!), and select the exported file and send the 
POST command.  This is very easy if there's one file for all the 
resources.  If it's one at a time, it's quite a bit more painful (the 
degree of pain is linear in the number of resources!).  Since it's "just 
as easy" for the server to handle the multiple posts (well, with the 
exceptions about error handling noted earlier of course!! nothing is 
really easy!), this would help customers put tools together easily, which 
is the point of OSLC.  And the error handling is a small problem for a 
server writer (compared to all the error handling you have to do anyway to 
make sure the POST is valid), at the saving for multiple end users.

I'd be happy with this being a "should" or "may" in the spec rather than 
"must" (perhaps with some standard error message if it's not supported, or 
something in the services document, so that clients that are written in 
code can tell) and the receiveing vendor can decide if its customers would 
get value from it.

Andy Berner
Lead Architect, ISV Technical Enablement and Strategy
IBM Rational Business Development
972 561-6599
ajberner at us.ibm.com

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